The present invention is directed to telecommunication systems, and especially to telecommunication systems having geographic sensitivity for automatic call connection with receiving stations. The present invention is especially well configured for telecommunication systems dealing with special number telecommunication systems, such as abbreviated number emergency services notification and dispatch operation telecommunication systems. Such emergency services notification and dispatch systems are commonly known as 9-1-1 systems in the United States.
The present invention includes a system and method for enabling any abbreviated number (or other special number) geographically based routing in a manner that is cost effectively applicable to hybrid private/public telecommunication networks such as are found in today""s market. Thus, the present invention is advantageous for use by a public telephone service provider (such as an incumbent local exchange companyxe2x80x94ILEC), a competitive local exchange carrier (CLEC), an Internet service provider (ISP), a wireless service provider (WSP), a large enterprise customer using a private exchange such as a private branch exchange (PBX), a wireless traffic aggregator/reseller switching between various backbone providers, a satellite telephone service provider or any other telephone service provider that may have users, or customers, employing their service to access a special number service seeking assistance from a geographically proximate locus.
Telecommunication systems sensitive to geographic aspects have been proposed. In U.S. Pat. No. 4,757,267 to Riskin for xe2x80x9cTelephone System for Connecting a Customer With a Supplierxe2x80x9d, issued Jul. 12, 1988, a system is disclosed which contemplates using geographic information gleaned from a caller""s telephone number for use with a V-H (vertical-horizontal) data base for ascertaining which site to connect with the caller to ensure geographic proximity between the dealer at the selected site and the caller. The Riskin system depended upon entry of the telephone number information using DTMF (Dual Tone Multi-Frequency) signaling. If a customer entered his phone number using a dial phone, Riskin provided for connecting the caller with a human operator so that the human operator could enter the telephone number information using a DTMF entry device. The V-H data base disclosed by Riskin for use with his system was a complex transformation of latitude and longitude which was used by long distance telephone companies to compute the distance between a caller and a called party in order to assess the charge for a long distance call. Riskin used the V-H coordinate system to refer a caller to a dealer that was determined to be geographically closest to the caller. Riskin also disclosed using the DTMF phone number information to connect a caller with a dealer on a territorial basis to effect xe2x80x9cgift routingxe2x80x9d. According to Riskin""s disclosure, a dealer may be connected with a caller based upon the dealer""s proximity to an intended gift recipient who was identified by DTMF phone number information relating to the intended recipient.
Riskin""s invention provides only a coarse location based upon the caller""s telephone number in the format: xe2x80x9cNPA-NNXxe2x80x9d. In that format, xe2x80x9cNPAxe2x80x9d refers to xe2x80x9cNumber Plan Areaxe2x80x9d, commonly known as Area Code. xe2x80x9cNNXxe2x80x9d, the next finer number indicator within an Area Code, refers to a Central Office of the phone service provider. As a result, Riskin""s invention provides location only to the detail of an area served by a respective Central Office of a service provider. Such an area can often be a very large geographic expanse. Locating a dense population of service locations regarding proximity to a caller is problematic when the location indicator is coarsely defined, as is the case with Riskin""s system.
Emergency services notification and dispatch operations, commonly known in the United States as 9-1-1 Service, has its genesis in a 1957 recommendation by the National Association of Fire Chiefs for a single number for reporting fires. In 1967, the President""s Commission on Law Enforcement and Administration of Justice recommended that a single number should be established nationwide for reporting emergency situations. The use of different telephone numbers for different types of emergencies was considered to be contrary to the purpose of using a single, universal emergency notification number. Other federal agencies and several government officials supported and encouraged the recommendation. The President""s Commission on Civil Disorders charged the Federal Communications Commission (FCC) with finding a solution. In November 1967, the FCC met with the American Telephone and Telegraph Company (ATandT) to establish a universal number that could be implemented quickly. In 1968, ATandT announced the establishment of the number 9-1-1 as the emergency notification number nationwide. The 9-1-1 code was chosen because it was considered to be brief, easily remembered, and could be dialed quickly. It was also a unique number that had never been employed as an office code, area code or service code, and it met long range numbering plans and switching configurations of the telecommunication industry. The 9-1-1 number met the requirements of all parties, in government and in private industry.
Congress supported the ATandT plan and passed legislation allowing use of only the numbers 9-1-1 when creating an emergency calling service. The 9-1-1 number was thus established as a nationwide standard emergency number. The first 9-1-1 call in the United States was completed by Senator Rankin Fite in Haleyville, Ala., using the Alabama Telephone Company. Nome, Alaska Implemented 9-1-1 service in February 1968.
In 1973, The White House Office of Telecommunication issued a policy statement recognizing the benefits of 9-1-1, encouraging the nationwide adoption of 9-1-1, and establishing a Federal Information Center to assist governmental units in planning and implementing 9-1-1 service.
A basic 9-1-1 System provides for programming with special 9-1-1 software a telephone company end office (also known as a xe2x80x9ccentral officexe2x80x9d or a xe2x80x9cClass 5 officexe2x80x9d) to route all 9-1-1 calls to a single destination. The single destination was termed a Public Safety Answering Point (PSAP). In such an arrangement, all telephones served by the central office would have their 9-1-1 calls completed to the PSAP. However, the areas served by respective telephone company central offices do not line up with the political jurisdictions that determine the boundaries for which PSAP may be responsible. That is, a municipal fire department or police department may geographically include an area outside the area served by the central office, a condition known as underlap. Likewise, the municipal fire or police department may encompass an area of responsibility that is less expansive than the area served by the central office, a situation known as overlap. Further, the original basic 9-1-1 systems did not provide any identification of the caller; the PSAP human operator had to obtain such information verbally over the line after the call was connected. The major shortcoming of the basic 9-1-1 systems was that they could not support interconnection to other telecommunication providers such as independent telephone service companies, alternate local exchange carriers (ALECs), or wireless carriers. The xe2x80x9cbasicxe2x80x9d nature of the basic 9-1-1 system also indicates that the system does not have Automatic Location Identification (ALI) capability or Automatic Number Identification (ANI) capability with a call back capability.
Similar abbreviated number systems are in place for handling emergency service calls in countries other than the United States. The abbreviated number system established in Canada is the foreign system most similar to the system established in the United States. There are other abbreviated number calling systems in place in the United States and abroad for such purposes as handling municipal information and services calls (3-1-1) and for other purposes. All of these special, or abbreviated number call systems that have geographic-based content suffer from similar shortcomings in their abilities to automatically place incoming calls to an action-response facility geographically proximate to the locus of the caller. It is for this reason that the 9-1-1 emergency call system of the United States is employed for purposes of this application as a preferred embodiment of the system and method of the present invention.
Automatic Number Identification (ANI) is a feature for 9-1-1 services that allows the caller""s telephone number to be delivered with the call and displayed at the PSAP. This ANI feature is sometimes referred to as Calling Party Number (CPN). The feature is useful for identifying the caller and, if the caller cannot communicate, for callback. A signaling scheme known as Centralized Automatic Message Accounting (CAMA), originally used to identify the originator of a long distance call for billing purposes, was adapted to facilitate ANI delivery to the PSAP. CAMA uses multi-frequency (MF) signaling to deliver 8 digits to the PSAP. The first digit (called the Number Plan Digit-NPD) specifies one of four possible area codes. Digits 2-8 represent the caller""s 7-digit telephone number. The ANI is framed with a key pulse (KP) at the beginning and a start (ST) at the end in the format: KP-NPD-NXXXXXX-ST.
The multi-frequency (MF) signaling used in connection with the ANI feature is not the same as the Dual Tone Multi-Frequency (DTMF) signaling also encountered in telecommunication systems. Both signaling schemes use a combination of two specific tones to represent a character, or digit, but the tones are different. There are 16 DTMF tones (0-9, #, *, A, B, C, D); there are a greater number of MF tones (including 0-9, KP, ST, STxe2x80x2, STxe2x80x3, and others). DTMF tones represent signals from a user to a network; MF tones are control signals within the network. An enhanced MF arrangement has recently been used in connection with 10-digit wireless telephone systems.
The availability of the caller""s telephone number to the PSAP (the ANI feature) led quickly to providing the caller""s name and address as well. This was straightforwardly accomplished using the subscriber information stored by telephone companies based upon telephone number since the 1980""s. New equipment at the PSAP enabled queries of an Automatic Location Identification (ALI) data base using the caller""s number provided by the ANI feature to ascertain name and address information. The ALI databases are typically maintained by the respective telephone company serving the PSAP. This was an improvement, but a problem still remained where several telephone company central offices served a town or county. Other problems also developed with the growing volume of mobile callers using wireless phones, satellite phones and communications over the Internet. Information regarding the locus of the origin of the call merely identified the locus where the call entered the wireline network; even such limited location information is not always provided. No indication was presented to identify the geographic location of such mobile callers.
As the situation of multiple central offices serving a PSAP occurred more frequently, it was clear that it was inefficient to build communication trunks from several central offices to a PSAP. As a result the 9-1-1 Tandem was developed. With that equipment, trunks from central offices are concentrated at a tandem office (a 9-1-1 Tandem) from which a single trunk group serves a given PSAP. Often a 9-1-1 tandem comprises an otherwise common Class 5 telephone system end office (EO), with added software to configure it for 9-1-1 operations. Such concentration of trunks reduces size and cost of PSAP equipment. The tandem is a telephone company switch that provides an intermediate concentration and switching point. Tandems are used for many purposes, including intra-LATA (Local Access and Transport Area) toll calls, access to other local exchange carriers (LECs), and access to long distance carriers and telephone operators.
A significant development in 9-1-1 services has been the introduction of Enhanced 9-1-1 (E9-1-1). Some of the features of E9-1-1 include Selective Routing, ANI, ALI, Selective Transfer and Fixed Transfer. Selective Transfer enables one-button transfer capability to Police, Fire and EMS (Emergency Medical Service) agencies appropriate for the caller""s location listed on the ALI display. Fixed Transfer is analogous to speed dialing.
Selective Routing is a process by which 9-1-1 calls are delivered to a specific PSAP based upon the street address of the caller. Selective Routing Tandems do not directly use address information from the ALI database to execute decisions regarding which PSAP to connect. Recall that emergency services (Police, Fire and EMS) are typically delivered on a municipality basis. Often there will be one Police Department (e.g., municipal, county or state), but there may be several Fire Departments and EMS Agencies. The town will be divided into response areas served by each respective agency. The response areas are overlaid and may be defined as geographic zones served by one particular combination of Police, Fire and EMS agencies. Such zones are referred to as Emergency Service Zones (ESZ). Each ESZ contains the street addresses served by each type of responder. The ESZs are each assigned an identification number (usually 3-5 digits), known as Emergency Service numbers (ESN).
The Assignment of ESZs and corresponding ESNs enables the compilation of selective routing tables. The street addresses are derived from a Master Street Address Guide (MSAG), a data base of street names and house number ranges within associated communities defining Emergency Service Zones (ESZs) and their associated Emergency Service Numbers (ESNs). This MSAG enables proper routing of 9-1-1 calls by the 9-1-1 tandem; this is Selective Routing as implemented in a 9-1-1 system. Thus, the telephone company must have an MSAG valid address to be assigned the appropriate ESN for selective routing purposes and that information must be added to the 9-1-1 ALI database. It is by using such information that the selective routing capability of the Selective Routing Tandem can properly route a 9-1-1 call to the correct PSAP. If the information is not available in the ALI database, the record is placed into an error file for further manual handling.
A portion of the ALI database may be loaded into a Selective Routing Data Base (SRDB) for use by the 9-1-1 Tandem. The SRDB may be located in the Tandem, in an adjunct processor, or in the ALI database.
Reliability is a very important factor considered in designing 9-1-1 systems. One approach to providing reliability is to provide diversely routed trunk groups from each central office to its respective 9-1-1 Tandem. Preferably, each trunk group is large enough to carry the entire 9-1-1 traffic load for the respective central office. However, some systems are designed with less than full traffic capacity on trunk groups to xe2x80x9cchokexe2x80x9d or xe2x80x9ccongestion managexe2x80x9d incoming calls to a tandem in order to avoid overloading a PSAP. In some arrangements, parallel 9-1-1 Tandems are provided so that a central office has capable 9-1-1 Tandem ready for use (albeit with 50% call handling capacity) without interruption if one of the 9-1-1 Tandems fails. Switched bypass to an alternate 9-1-1 Tandem, commonly using digital crossover switches, is another approach to providing reliability in 9-1-1 systems.
Another approach to providing redundancy and robustness for a 9-1-1 system is the employment of Instant Network Backup (INB). Using INB, if a call does not complete to the 9-1-1 network for any reason (e.g., trunk failure, facility problem, 9-1-1 Tandem failure or port failure), the INB takes over and completes the call to a predesignated 7- or 10-digit number. Using this INB alternate path, ANI and ALI information are not delivered, but the call is completed to a local public safety agency, usually the local PSAP.
The interface between Operator handled calls and a 9-1-1 system is addressed in several ways. One system provides a direct connection between an Operator Tandem and the 9-1-1 Tandem. The operator forwards the call with the caller""s ANI to the 9-1-1 Tandem. The 9-1-1 Tandem treats the call as though the caller had dialed the call. A second way to effect the desired interface is by using pseudo numbers. A pseudo number is a number that, when dialed, will reach a specific PSAP as a 9-1-1 call. Pseudo numbers have some special ALI information associated with them; for example, there may be a pseudo number associated with each municipality in a state. Dialing the pseudo number, usually from outside the LATA (Local Access and Transport Area), will generate a 9-1-1 to the PSAP for that municipality. The ALI display will indicate that it is a third party conference call from an unknown address in that town. The caller is not identified, but the call goes to the PSAP where the caller is believed, or claims, to be. Pseudo numbers are useful for Alternate Local Exchange Carrier (ALEC) or Competitive Local Exchange Carrier (CLEC) operators who may be located anywhere in the country.
A third method for effecting an interface for operator handled calls with a 9-1-1 system is through the public switched telephone network (PSTN), dialing the directory number for the PSAP. This is often referred to as the xe2x80x9cback doorxe2x80x9d number by ALEC and CLEC operators.
The same issues encountered in implementing a 9-1-1 system for identifying user location are also extant in other telecommunication systems where user location (or other locations) are important. As mentioned above in connection with the Riskin ""267 Patent, marketing decisions, dealer contact actions and delivery actions may be more informedly effected using location information obtainable from a properly featured telecommunication system. According to Riskin, such geographic location information is of value even when it is coarse information suitable only for locating a caller within a telephone service provider central office service area.
The advent of wireless communications has further exacerbated the difficulty of ascertaining caller location in telecommunication systems. The xe2x80x9cpatchworkxe2x80x9d solutions described above regarding 9-1-1 systems have been mirrored in other special, or abbreviated number systems to a significant extent. The xe2x80x9cpatchworkxe2x80x9d solutions have created a capability-limited telecommunication system that cannot ascertain geographic information as fully or as easily as it should for all types of callers. This capability limitation has been especially felt in connection with wireless telephone systems. The system is overly dependent upon human intervention to properly route calls to appropriate receivers, such as a proper PSAP. New modes of communication, such as Voice Over IP (Internet Protocol), further contribute to telecommunication traffic not identifiable regarding geographic origin using present telecommunication routing systems.
Similar limitations will likely occur in other abbreviated number, or other special number, telephone systems handling location-based calls with resulting adverse limitations. Other such abbreviated number systems include emergency call systems in countries other than the United States, abbreviated number calling systems for reaching telephone maintenance services, abbreviated number calling systems for municipal information and services, and similar systems.
There is a need for an improved telecommunication system and method with geographic sensitivity that can be employed for abbreviated number systems and other telephone systems to ascertain user location or other geographic information with less human intervention than is presently required.
There is also a need for an improved telecommunication system and method with geographic sensitivity that can be employed for abbreviated number systems and other telephone systems to ascertain user location or other geographic information when involving wireless, Internet, satellite or other non-geographically fixed communication technologies.
The present invention is particularly directed to routing of special number calls in a telecommunication network. Standards presently exist that establish routing procedures and systems for special number wireless mobile calls to a public safety call center, or a public safety answering position (PSAP). Special number calls, as used in the present application includes any abbreviated number in use for reaching a particular service, such as maintenance services, phone company billing services, or emergency services (e.g., 9-1-1 in the United States).
For purposes of explanation of the present invention, an exemplary explanation in terms of an emergency service call in the United States (i.e., an E9-1-1 call) will be described. One skilled in the art of telephone systems and methods will readily recognize the applicability of the teachings of the present application to other special number systems in various phone systems and jurisdictions.
Present systems and procedures for effecting wireless mobile abbreviated number routing, such as E9-1-1 calls in the United States, suffer from significant shortcomings because they are implemented in technology that is years, if not decades old that is still employed today for wireline E9-1-1 call processing. Presently deployed systems and methods for wireless mobile emergency call processing are more data intensive than is necessary. As a result, the call processing effected by such old systems and procedures is slow and inefficient.
There is a need for improved efficiency and speed in call processing for mobile wireless special number calls, such as E9-1-1 calls, in telephone networks.
A system for routing mobile special number calls in a telecommunication network includes: (a) a mobile call originating station for originating a special number call from a call locus; the mobile call originating station includes a position determining unit; (b) a mobile switching station for receiving the special number call; the mobile switching station assigns a temporary identifier for the mobile call originating station at least during the special number call; (c) a mobile geolocation system coupled with the mobile switching station; the mobile geolocation system cooperates with the mobile switching station to query the position determining unit for origination geographic information relating to the call locus; and (d) a special number call service station coupled with the mobile switching station; the special number call being routed to the special number call service station according to at least some of the origination geographic information.
The method includes the steps of: (a) providing a mobile call originating station for originating the special number call from a call locus; the mobile call originating station includes a position determining unit; (b) providing a mobile switching station for receiving the special number call; the mobile switching station assigns a temporary identifier for the mobile call originating station at least during the special number call; (c) providing a mobile geolocation system coupled with the mobile switching station; the mobile geolocation system cooperates with the mobile switching station to query the position determining unit for origination geographic information relating to the call locus; and (d) providing a special number call service station coupled with the mobile switching station; the special number call being routed to the special number call service station according to at least some of the origination geographic information.
Prior art special number, or abbreviated number telecommunication systems receive some geographic related information. In some presently existing situations, mostly involving wireline telephone connections, geographic information received is adequate to accomplish required routing. In other presently existing situations, such as in situations requiring rerouting of calls to wireless service providers (WSP), to private branch exchanges (PBX), to overcome a problem in the normal wireline connection, or for other special situations, required call routing is difficult. The degree of difficulty varies depending upon whether adequate arrangements were made beforehand between respective PSAPs. In such difficult rerouting situations, human operators at special number answering stations must effect connection with geographically appropriate special number action stations in order that appropriate action agencies geographically proximate to the caller initiating the special number call may be responsively employed. In some systems the human operator effects the required routing by pressing a button, or a plurality of buttons. However, in order to ascertain the desired destination of the call, the human operator must read a screen or consult a list or directory. Such consulting to ascertain desired routing decisions consume time and offer opportunities for human errors.
There is a need for an automatic-connection capability for effecting the desired geographically proximate call completion with little or no human operator intervention required. Automatic routing based upon geographic information provided with call information is known for generalized telephone network systems. There is a need for employing the advantages proven to be attainable by today""s generalized telephone network systems technology to the 1960""s and 1970""s xe2x80x9cpatchworkxe2x80x9d system structure presently employed for special number communication systems in the United States.
The special number handling and routing system of the present invention offers numerous advantages over present special number systems. The present invention contemplates adding special number handling capabilities to a telecommunication network switch, such as selective routing, enhanced Automatic Location Identification (ALI), mapping, and other capabilities peculiarly applicable to special, or abbreviated number call handling. Such added capabilities at the special number system network switch level provide significant flexibility to handling of special number calls by a telecommunication system. For example, such integration of special number call handling capability in a telephone network obviates the need for choking through overflow routing, queuing, interactive voice response (IVR) or granular plotting of calls for filtering. The new system of the present invention minimizes the difficulty in coordinating choking across a variety of Local Exchange Carriers (LECs) that may route calls to a 9-1-1 tandem. The new system provides each carrier (LEC) with an appropriately engineered network access to manage call volume and distribute calls to call takers in special call answering stations, such as Public Safety Answering Positions (PSAPs), or route the calls to queues or IVRs, according to extant service policies.
Another important capability provided by the system of the present invention is an ability to manage multiple special number answering stations (such as PSAPs) for disaster recovery, mutual aid, or other cooperative activities. The system of the present invention facilitates sharing of data screens, call screens, dispatch screens and other commonalities that may be instituted when needed without necessarily requiring voice connection. The system of the present invention also creates a more robust system better able to resist interruption during disaster operations. Integrating special number handling systems with a telecommunication system at the special number system network switch level provides significantly greater flexibility and speed in traffic rerouting to avoid network breaks, and similar disaster-related problems.
Also of significance, such high-level integration of special number handling systems with public telecommunication systems makes it more likely that improvements and advances in communication technology will be employed for upgrading special number handling in the future. If special number handling systems are not xe2x80x9cmain streamxe2x80x9d applications integrated within the public phone system, there may be a tendency for them to evolve differently than the public telephone system, and future compatibility between systems would be ever more difficult.
Further, high level integration of special number call handling capabilities within the main stream public telephone network facilitates easier inclusion of diverse special call handling agencies within the system, such as colleges, animal control agencies, poison control agencies and others.
By way of example, from a public safety perspective, two significant improvements provided by the system of the present invention are (1) interconnected PSAPs with click-through routing enabling that treats all PSAPs as one large logical PSAP across political jurisdictions and carrier service providers"" boundaries; and (2) a significantly more reliable network with added redundancy, ability for calls to overflow and be backed up (e.g., eliminating choking) and enhanced network management capabilities using the latest technologies. These advantages are realized because the system of the present invention employs 9-1-1xe2x80x94tandems interconnected with all other 9-1-1 tandems and network switches at high level interfaces enabling more varied data types at faster speeds in the public telephone network. In its preferred embodiment, a 9-1-1 tandem configured according to the present invention is a stand-alone switch apparatus.
It is, therefore, an object of the present invention to provide a telecommunication system and method for handling special, or abbreviated number calls that has geographic sensitivity.
It is a further object of the present invention to provide a telecommunication system and method for handling special, or abbreviated number calls that can automatically connect a caller with a geographically proximate action agency with no human intervention using geographic information included with call information.
It is yet a further object of the present invention to provide a system and method for routing special number calls in a telecommunication network that is faster and more efficient than is presently extant.
Further objects and features of the present invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings, in which like elements are labeled using like reference numerals in the various figures, illustrating the preferred embodiments of the invention.